Crohn’s disease and ulcerative colitis can cause a number of symptoms which are often not talked about. They can be awkward and cause embarrassment but are usually an everyday occurrence. Awareness around the symptoms of IBD is important to help understand the conditions.

Not everyone with IBD will be affected in the same way. There are many different symptoms associated with IBD and the symptoms can vary in severity from person to person and can also change over time. Common side effects, such as diarrhoea and pain, can often be mistaken for other conditions, such as IBS (Irritable Bowel Syndrome), which can delay an accurate diagnosis. Always take note of your symptoms, their frequency and severity and any patterns you have noticed, so that you can discuss them with you doctor and they are more likely to diagnosis your condition.

Symptoms can range from very mild to severe. Symptoms can also change over time and you may go through periods with few or no symptoms, known as remission, followed by times when symptoms are worse and harder to manage, known as an active phase or a flare up. Symptoms can also vary depending on how much of your digestive system is affected.

The most common symptoms of Crohn’s disease and ulcerative colitis, during an active phase, are:


This is a common symptom and can be accompanied with an urgency to use the toilet which cannot be controlled. Patients can experience diarrhoea 6 or more times a day during an active phase. This is sometimes mixed with blood, mucus and pus, from the ulcers that can form on the surface of the gut.

Pain in the abdomen

Another common symptom, this can feel like severe cramps and often occur before going to the toilet. The pain is caused by the inflammation of the gut and is often felt a couple of hours after eating. During an active period, the pain can cause a loss of appetite, or patients may avoid eating to avoid the pain of cramps.


This can be due anaemia (see below), from the side effects of some medication used to treat IBD or from a lack of sleep if symptoms keep patients up at night. A lack of absorption of nutrients in the digestive system, caused by inflammation, can also contribute to feelings of lethargy.

Feeling unwell

Some people may develop a temperature and have a general feeling that something isn’t right.

Loss of appetite and weight

Inflammation in the gut may result in the body not absorbing nutrients from food. Pain and bloating after meals may also cause some patients to avoid food.


This can be caused by a loss blood in stools, if you are not eating much due to feeling unwell, or if the inflammation in the gut is preventing uptake of nutrients.

Mouth ulcers

These are usually caused when patients begin to feel run down.

Some people (particularly with Crohn’s disease) may go on to develop complications, which can include:


This is a build-up of scar tissue in the bowel, which has formed as a result of ongoing inflammation and then healing. Strictures can cause a narrowing of the bowel at a certain point.


A fistula is an abnormal channel or passageway connecting one internal organ to another, or to the outside surface of the body.

Crohn’s disease and ulcerative colitis can sometimes affect other parts of the body, including:


Inflammation of the joints, often known as arthritis, means that fluid collects in the joint space causing painful swelling. It usually affects the large joints in the arms and legs, including the elbows, wrists, knees, and ankles.

Eye inflammation

The most common eye condition affecting people with IBD is episcleritis, which affects the layer of tissue covering the sclera, the white outer coating of the eye, making it red, sore, and inflamed.


IBD can cause a condition called erythema nodosum, which causes tender swellings on the legs.


People with IBD are at a greater risk of developing weak or brittle bones, due to the poor absorption of key nutrients in the digestive system.


Hair loss is common in IBD patients and may be due to the stress of living with a chronic condition, or due to the poor absorption of key nutrients.


IBD affects blood circulation and patients are more likely to suffer a Deep Vein Thrombosis. This is a risk if you have experienced an active phase of the condition and are spending long periods in bed. Any leg pain should always be investigated by a doctor.

There are several factors that have been identified that can impact a flare up and make symptoms of IBD worse. Identifying and managing these factors is an important part of managing the condition. These can include:

Missing medication

Missing a dose of your prescribed medication, even during a period of remission, or taking the wrong dose, can cause a flare up. If you are taking your medication currently, and you experience a flare up, talk to your doctor about changing dose, frequency, or type of medication.


Antibiotics are prescribed to treat a bacterial infection, but they can interfere with the normal bacteria in your gut. An imbalance of your healthy bacteria can cause diarrhoea or trigger inflammation as a response to the growth of bacteria. Always talk to your doctor if you experience a flare up when taking antibiotics.


Although emotional and physical stress do not cause IBD, it can impact your symptoms. A stressful event or emotional time can be problematic, so patients are advised to develop some stress-management techniques or identify a support system.


It is known that smoking can cause IBD and can trigger a flare up in IBD patients. Patients who smoke experience more active flare ups, are more likely to require surgery, and are more likely to require medication to control their disease. Once an IBD patient quits smoking, they report fewer flare ups and reduced need for medication.


No specific food can cause IBD but paying attention to foods that cause a flare up, known as trigger foods, can help you manage symptoms. Keeping a close eye on diet can also ensure that nutrients are replaced. Dieticians recommend keeping a food diary to see how the foods in your diet affect your symptoms. By identifying what causes your symptoms to get worse, you can work out what to avoid. Many symptoms of IBD can cause a loss of appetite. This, coupled with reduced uptake of nutrients in the gut due to inflammation, means it is vital that patients have a well-balanced diet to avoid nutrition deficiency.


It is not known exactly what causes Crohn’s disease and ulcerative colitis. The conditions were rarely seen before the 20th century and emerged when hygiene standards and urbanisation changed the way we live our lives.

Ulcerative colitis was first described by physicians in the UK in 1875, who distinguished it from other infectious gastrointestinal diseases. Crohn’s disease was first identified by a group of doctors in 1932, including Dr Burrill Crohn, who identified that the symptoms their patients were experiencing were not down to intestinal tuberculosis, as previously thought.

For a long time, IBD was believed to be an auto-immune disease. An auto-immune disease is a condition in which your own immune system attacks your body, as it incorrectly believes it is under attack. Diet and stress were also previously thought to be causes of IBD, but doctors now know that while they may aggravate IBD, they are not the cause.

Lots of research has since been done to explore likely causes. It is now believed that it a combination of factors, including environmental triggers and an abnormal immune system reaction, together result in the condition. This abnormal reaction of the immune system is caused by the body thinking a harmless environmental trigger, is attacking it, and the immune system ‘malfunctions’. This leads to an influx of white blood cells in the gut which try to attack the incorrectly identified trigger. This causes inflammation and upsets the gut’s normal function, and is the cause of side effects, such as pain, swelling and diarrhoea. Genetics may also play a part, particularly in ulcerative colitis. Environmental triggers could include:

  • Viruses
  • Bacteria
  • Stress
  • Diet
  • Smoking
  • Taking certain medications

Risk Factors

There are certain risk factors that may increase your chances of developing IBD. The biggest risk factors are:


Smoking is one of the biggest risk factors for developing Crohn’s disease. It is also known to increase the pain associated with Crohn’s disease as well as other symptoms and can increase the risk of complications associated with the disease.


Although IBD can be diagnosed at any age, it usually starts before the age of 35, and is most commonly diagnosed in adolescents and between the age of 20 and 30.


The chance of developing IBD is equal between men and women, but ulcerative colitis is more common in men, while Crohn’s disease tends to affect more women. The reason for this is not known.


People who are white and from Northern Europe or North America tend to be more likely to develop IBD, as well as people in the Ashkenazi Jewish population. This is believed to be down to genetics and from living in more industrialised areas.

Family History

Genetics is believed to play a role in causing IBD, and people who have a first degree relative, which includes parents, siblings, or children with IBD are at a higher risk of developing it.


People living in urbanised locations are at a higher risk. This is believed to be due to pollution, lifestyle and diet choices, including an increased consumption of fat and processed food.


Getting an accurate and timely diagnosis for IBD is crucial to successful management and treatment of the disease. Discussing symptoms can be embarrassing and patients are often reluctant to share the full details with their physician. But delaying a visit to the doctor, ignoring symptoms, or not discussing them in full can make an accurate and timely diagnosis a challenge. A delayed diagnosis may lead to more severe symptoms, development of complications, and increase the need for surgery.

Your doctor may suspect that you have Crohn’s disease or ulcerative colitis if you have abdominal pain and diarrhoea with bleeding. You will be asked about your individual symptoms and any family history. Be sure to share as much detail as possible about your symptoms, including frequency, severity, and any patterns in occurrence. This will help your doctor to identify any warning signs of IBD and ensure you are given the correct attention and if necessary, a referral to a specialist for diagnosis.

You may then need to have some tests to confirm a diagnosis. The tests you have will depend on your individual case, but they may include:

Blood tests

A blood test can indicate whether your body has inflammation and whether you are anemic. Your doctor can also use a blood test to check the function of your liver and kidneys.

Stool tests

A stool test can check for blood and signs of infection.


This involves an endoscope, a long, thin, flexible tube with a camera on the end, to look inside the gut. Depending on where your doctor suspects the inflammation is, the endoscope may be inserted through your mouth or anus. It may be a little uncomfortable, so a sedative is often given.


An x-ray of your abdomen may be taken to help diagnose IBD. Once a diagnosis is made, a CT scan can be used to take more detailed images of a specific part of your digestive tract.

MRI scan

Using magnetic fields and radio waves, an MRI is an effective way of scanning the whole body to look for inflammation in the gut, scarring, fistulas and abscesses.


An ultrasound is an external scanning device that can help detect areas of inflammation in the bowel, detect areas of fluid build-up and any possible abscesses and fistulas.


Any treatment that your doctor recommends will depend on individual symptoms, which area and how much of the digestive system is affected and your medical history. There is no one standard treatment that will work for everyone, and it may be a combination of different treatment options that can help control your symptoms. There are many effective options available, which include the use of medication, changes to diet and nutrition and if needed, surgery, which can vastly improve quality of life for people living with IBD.

Medication is usually offered first to suppress the abnormal inflammatory response that your body is displaying in response to certain triggers. Reducing the inflammation in the digestive tract that causes the pain, swelling and redness will control symptoms like diarrhoea and pain and allow the gut to heal. Medication can help IBD patients into a period of remission when the symptoms are less severe and have less of an impact on day-to-day life.

Medication can also decrease the frequency of flare ups. If your body can tolerate this medication, you will probably stay on it to prevent you entering an active phase, or flare-up. This is known as a maintenance dose.

Medicines to target the immune system

The medications used to treat IBD are called immunosuppressants and stop your body’s immune system attacking the gut in response to the inflammation that IBD has caused.


Biologics are usually given to people who have moderate to severe cases of IBD, when other treatments have not worked. They are called biologics as they are made using living organisms, such as cells, which produce proteins as the active ingredient. Biologics work by blocking the malfunction of the immune system, that is attacking an incorrectly identified foreign object in the gut and causing inflammation as a response. This helps improve symptoms of IBD. Biologics have been shown to be effective in improving gut symptoms and can help to maintain periods of remission. There are two classes of biologics and they work in different ways:

Immunosuppressants that block cytokines

Cytokines are proteins that are produced in an immune response. By blocking their activity, the immune response is suppressed. IBD patients are thought to produce too many of these proteins, leading to inflammation.

Immunosuppressants that block white blood cells

White blood cells are also produced during an immune response. Again, IBD patients are believed to produce too many white blood cells, so some biologics work to stop their movement to the gut, thus stopping the inflammation caused by the immune response.

Medicines to treat symptoms

These are medicines that are given to treat the symptoms of IBD, like pain and diarrhoea. They are given for short-term relief from symptoms but do not treat inflammation. Although some of these medicines are available over the counter, you must always talk to your doctor before taking any medication, as some symptomatic drugs can cause serious side effects, particularly during flare ups. Symptomatic medicines can include:


Help to reduce diarrhoea by slowing down the contractions of the bowel, meaning that food stays in the bowel for longer, allowing more water to be absorbed, and allowing the body to produce firmer, less frequent stools. Antidiarrheals should NOT be taken during a flare up as they can cause serious complications.


Work by reducing the spasms of the intestines, which reduces painful cramps.


Paracetamol is used to treat the pain in the stomach or joints, associated with IBD. Ibuprofen should be avoided as it has been shown to induce flare ups. If you need longer term relief from pain, particularly following surgery, always talk to your doctor.

Bulking agents

When taken with water, these granules swell inside the gut to thicken watery stools. They should not be used by anyone who has a narrowing of the bowel, known as a stricture.


These are given to provide relief from constipation when you are passing stools infrequently or experience strain when going to the toilet.


These are often prescribed to treat complications of IBD such as abscesses or fistulas, to prevent an infection. As one of the causes of IBD may be the body’s reaction to unharmful bacteria in the gut, antibiotics can help control symptoms by reducing the number of bacteria and suppressing the immune response. The use of antibiotics has shown no benefit in ulcerative colitis but can be effective in people with Crohn’s disease that is affecting the colon (known as Crohn’s colitis).


Steroids are often given when experiencing a flare up as they can act quickly to reduce inflammation by controlling the immune response and can induce a period of remission. Most patients with IBD will be given steroids at some point in their treatment journey, but they have a high risk of side effects and cannot be taken long-term. Steroids are synthetic versions of the hormones your body produces naturally. Steroids can be taken intravenously, orally or rectally, depending on your condition. No more than two steroids treatments should be taken in one year, and they may not work for everyone. If you see a different doctor, always tell them about any steroid treatment you have received. Side effects are common, and can include cosmetic changes, mood changes, risk of infection and joint, bone or muscle problems. Always alert you doctor to any side effects and never stop taking a dose mid-treatment.

Maintaining good nutrition is vital for people with IBD. Inflammation in the digestive tract can prevent the absorption of key nutrients from food, leading to anemia, feelings of lethargy (tiredness) and a general reduction in overall health. The pain felt in the abdomen can also cause IBD patients to lose their appetite, which can result in weight loss and fatigue. People may also avoid eating food to avoid the side effects such as diarrhoea which is often experienced after a meal. Nutritional or dietary supplements are an effective treatment option, particularly in children.

Please note, nutritional treatments should only be taken after seeking advice from your doctor.

Enteral nutrition

This involves a liquid-only diet for a number of weeks, to give the gut a rest following a flare up. No food is eaten, and the liquid, known as exclusive enteral nutrition, provides all the nutrients the body requires. Some people take the liquid on top of a normal diet to boost the amount of nutrients they are consuming. This can also be beneficial for children as it promotes normal growth. This treatment is effective for people with Crohn’s disease.


Adding probiotics to your diet can help improve the health of your gut. Illnesses like IBD can cause an imbalance in the natural bacteria found in the gut, so taking probiotics supplements can help increase the number of these friendly bacteria.

Iron supplements

A deficiency in iron can lead to anemia, which is common in IBD patients, and can cause tiredness. Iron supplements can boost iron levels, but often cause side effects such as constipation, so always discuss this with your doctor. In severely anemic patients, an infusion of iron can be given directly into the blood stream.

Calcium and vitamin D

One of the areas of the body that IBD can affect, outside of the digestive system, is the bones, and they can become weakened. Calcium and vitamin D supplements can help to protect bones.

Vitamin B12

Given as an injection, vitamin B12 is given to help increase the number of red blood cells and maintaining a healthy nervous system. For people with Crohn’s disease, where inflammation affects the ileum (or it has been removed through surgery), vitamin B12 deficiency is common.

Sometimes surgery is required when flare-ups are having a serious impact on quality of life. It may also be necessary if your body isn’t responding well to medication, or you are experiencing unpleasant side effects. Surgery is less common these days, thanks to advances in medicine, but it can offer life-changing relief to some people. The surgery you may require will depend on the condition you have and the area of your digestive system that it is affecting. Surgery can offer relief from pain, reduce severity of symptoms, and can allow patients to stop taking medication in some instances.

Many surgeries for IBD are carried out using laparoscopy (or key-hole surgery) and are minimally invasive. This means that small incisions are made instead of one large one. This helps speed up recovery time, can reduce pain after the surgery, and can mean a shorter stay in hospital.

All surgery carries a risk, usually associated with the use of general anaesthetic, or the risk of complications after surgery. Your doctor will discuss any risk with you before considering surgery and will help you decide what is right for you and whether the benefits of surgery will outweigh these risks.

The most common type of surgery are:


This operation involves the opening of the intestine to treat strictures and blockages, without the need to remove any part of the intestine. This procedure allows food to then move more freely through the gut. If the stricture is long, a resection is given, which involves a surgeon removing the damaged area and joining it back together.

Ileocecal resection

Inflammation can be severe at the point where the small intestine (terminal ileum) meets the large intestine (caecum), and it may be necessary to remove this section and join the two healthy parts together.

Limited right hemicolectomy

This procedure involves removing part of the colon; the first part of the colon on the right side of the body and joining it up to the remaining healthy section.

Colectomy with ileostomy

This involves the removal of all, or most of the colon. This is necessary when Crohn’s disease is very severe. The remaining end of the colon is then brought out through an opening in the abdomen and a stoma bag is needed to collect waste (see below for information on stomas). If the rectum remains healthy, then it can be possible to join the end of the small intestine (ileum) to the rectum rather than taking outside of the body. This procedure is called a colectomy with ileo-rectal anastomosis.

Proctocolectomy and ileostomy

If the rectum is also affected, then it may also need to be removed. A surgeon will then create an ileostomy to direct waste out of the body.

Restorative Proctocolectomy with ileo-anal pouch

This is often referred to as pouch surgery. It can take several stages and firstly involves removal of the whole colon, except the rectum and anus, and an ileostomy is formed to collect waste outside of the body. In a second operation, a pouch is made from the end of the small intestine (ileum) and connected to the anus, with the aim of replacing the function of the rectum and storing faeces. This surgery allows stools to pass out of the body in a normal way.


Surgery for IBD can sometimes require a stoma bag. If the intestine is brought to the surface through a hole in the abdomen, via ileostomy surgery, a bag is used to collect waste. The bag will need to be emptied throughout the day and changed several times a day, but this is dependent on the type of surgery you have had, and the type of bag fitted.

Getting used to life with a stoma can take time. It may present challenges and cause emotional issues. However, most patients find that once they have recovered from surgery and have come to terms with the idea of living with a stoma, they offer a huge improvement to quality of life. Symptoms of IBD become less worrying and you can carry on with normal activities.